Hmm, maybe someday. At least this would be easier than 4D faceting, which is more dependent on understanding the full symmetry of the model in question. Currently Stella doesn't really know the full symmetry of 4D models like it does for 3D models. Cell/face/edge/vertex types are all established based on various heuristics, but could still be wrong occasionally. Ideally you will (sometimes at least) want to augment to all cells of the same type at the same time.

The only problem then would be matching orientation between each one, but maybe this can also be based on a few heuristics (eg matching neighbouring cell types) and luck of the draw (in most useful cases I suspect there will only be one orientation anyway, and otherwise matching neighbours is probably enough).

Hmm, well in 3D faces at which two polyhedra are augmented together are normally removed from the final model, though there's an option to leave both in as a duplicate face (leaving just one copy in would lead to a non-manifold surface, with potentially an odd number of faces meeting at some edges). I wonder whether the cells at which polychora are augmented should be removed or duplicated or something else?